shocking results

hi

just had my bike dyno jetted today and was quite shocked at results. i thought my bike was pretty spot on i ve done all free mods and added full fmf system (powerbomb and q4) removed smog pump and added jd jetting kit and followed instructions and dyno shows jetting to be miles out standard is 162mj, jd recommends 165mj and dyno says need to change to 160mj i thought bike ran good with jd recommendations but cant wait till leaned up to see full power i m gonna alter mjet b4 next run on wed and their gonna fine tune needle height(cuts costs down ha ha ha) on the day

kenny:banghead:

You may want to spend a bit of time reviewing some old jetting posts by one of your fellow countrymen " Taffy". He was very knowledgable and adamant about what he believed to be the correct way to jet these bikes. Do a search on his name and go back to the posts in '02 a give 'em a read. WR Dave.

hanks for reply wrdave but is it relevant, i ve done a search on taffy s posts and most seem to be in regard to fuel tanks the only 1 i found regarding tuning is

Taffy,

It's great to see you here! I hope you're doing well.

Times have changed and none of the manufacturers use the version of FCR carb you once tuned with except for the DRZ. No main air jets to replace now and the accelerator pumps are tuned by diaphram rivet lengths and Leak jets in the float bowl instead.

Yes, Jetting Q's is still here, and will be for years to come.

James

that was from mr dean himself sorry if i m too dumb to find what you mean but do you have a link, all i was trying to get at was paid money for jd kit and its no where near instructions i coulda saved money and standard jetting woulda been closer

It's still relevant, the carb is slightly different ,but the engine doesn't know what carb is feeding it, just that it's getting enough fuel to do the job properly. Anyway I don't have any specific Taffy posts that I can find right now , but he was always jetting leaner than anyone else and getting good results. He was down to a 38 pilot jet and 158 main jet in your area. I'm not familiar with your elevation changes over there but that's pretty close to what I'm running in my 450 and it's got very good throttle response and performance. WR Dave.

cheers dave

i m still on 48 pilot but have just dropped to 160 mj and difference is unbelievable it s now starting to come up in fourth, this is more like i was expecting bike to run. still dont think its quite right but guess fine tweeking next wed on dyno will sort it out by the way elevation is sea level and humidity 54% with temp of69.91F cant belive how far out jd s jetting guide was wish i d followed indys he s a dam sight closer. i hope 1 day ill be as knowledgeable as yourself guess you ve been playin with these for quite i while this is my first 4 stroke and i m pretty impressed oh by the way output was 46.02 hp

kenny

Kenny - Would you mind listing your exact carb settings (main, pilot, leak and type/position of needle) with your seat-of-the-pants and/or dyno impressions for each change you make. Please start with your stock settings and go from there. Thanks - much appreciated.

I'm currecntly running 165/45/JD Red 5th notch/70 leak and even though the bike performs well, I feel it's too rich. Thanks.

hi sxp

this is where i m at

ais removed

all free mods

zip ty fuel screw 1 3/4 turns from seated

gray wire disconnected

fmf powerbomb header

fmfq4 tailpipe

160 mj

48 pilot

all other jetting is standard

red needle 4th clip from top

as in previous posts scrapped jd s recommendations although bike started and run real well by dropping mj from 165 to 160 bike has new lease of life for the first time since i ve owned it i m shaking after last ride ha ha ha ha

i ve gotta wait till next week for dyno only booked in for diagnostic 2day as earlyier stated i altered mj as they instructed cos they charge £37 per hour and i can do this myself they will tweek next week just trying to get bike into right area for them i ll post dyno runs when camera is fixed

seriously though its money well spent

kenny

I really gotta think that you need to drop at least one size on your pilot jet to a 45 or 42 as well. On mod I didn't see you mention was wether or not you disconnected the ACV circuit. I did mine just by flipping the diaphram over. I think it gives slightly hard to understand jetting results when it is still functioning and letting air into the intake on decel. Again this is just my .02 - WR Dave. :thumbsup:

I read this and thought i would try the 160 m/j, I found my bike ran poor and lacked the power that i had with the 170 m/j.

I really gotta think that you need to drop at least one size on your pilot jet to a 45 or 42 as well. On mod I didn't see you mention was wether or not you disconnected the ACV circuit. I did mine just by flipping the diaphram over. I think it gives slightly hard to understand jetting results when it is still functioning and letting air into the intake on decel. Again this is just my .02 - WR Dave. :prof:

Mine needed a #40 when I did that. :thumbsup:

your right wrdave i ve not done acv mod yet started to read up on it and got a bit lost with it all, think i understand the principles(leans up mix when you shut of throttle to stop backfire???) but could not follow instructions to well and i aint got a clue what jb weld is, would like to get it sorted b4 wed due to dyno run. i ll have another read today without the help of warm beer this time and see if i can string the sentences together, note to zehr i guess your bike lacks power with 160 due to atmospherics hum temp etc i am not trying to say i ve done a dyno and these results will work for anyone just simply that i was shocked that jd who produce kit etc are soooo far out there telling me to richen from stock when really i need to lean for me personally indys jetting guide is a lot closer, cant be to bad though a least i know liccle bit more bout bike now

kenny

I live in Canada and i'am at about 230 feet above sea level, not sure the moisture content here i would guess 50%. also why would changing the pilot jet make it run better? isn't that only for low end power?

hi

zehr i guess looking at my dyno sheet my bike is running richest between 5000 and 6000 rpm presume thats down to pilot jet now which i m gonna change tom what wr dave says makes sense now, i get the feeling he s pretty keyed up. gonna search forum and try to find dia of acv removal etc bit easyier to understand that way

kenny

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